bacon2109, Do I understand correctly from the link you provided that you have a total of 800g or 24oz of carbon on each side of your core? I think that's a light layup, and I don't think you are going to make it stiffer with fibers at 60 degrees. I think you should get some unidirectional in there.

If mast is critical for stiffness. The stiffer the better. The difference between too flexible and stiff is only a few hundred grams. My call is to make sure the mast is STIFF. If you want to skimp on weight take it out of the board, fuse and wings.

^
Uhm, man, try Levitaz. You'll be surprised. Yes, people actually race with those, so all torsion stiffness is questionable.

Earnestly, with all that carbon, 610 g/m2, we talking weight similar to ALU. Why bother than? Plus, ALU is way thinner.

BTW, 610g/m2 would be impossible to wrap.

If carbon is not wrapped around the LE, than all it does for torsion is up to the LE strength. If LE is just wrapped in UNI and eventually 45/45 (or whatever), the torsion max strength is coming from 45/45 fibers. Not UNI.

Downunder, what is your layup then? Are you saying you have less than 800g per side? That would be less than 4 layers of 6oz (200g) cloth per side. If so then what is your core? I think the layers that I wrapped around my leading edge were no more than 6oz/200g in weight, but there were quite a few

Mine has more than twice that amount of carbon over a corecell core, and it is way lighter than aluminum, especially if the Aluminum is full of water!

Also, you say "try Levitaz". I've never seen one, what are you saying about it - are they really flexible?

Hehe.... I have 800gm uni and 800gm twill in the mast.
Needless to say it doesn't break when I hit the sea floor, fish and submerged logs!
It also weighs heaps less than a alloy mast and floats.... so win win.